Venting means for containers



June 17, 1969 w KlNNAVY ET AL 3,450,305

VENTING MEANS FOR CONTAINERS Filed Oct. 12, 1966 s m m EY WV A N m K W sE M A J a JOHN J. BUCHANAN ATTORNEYS United States Patent 3,450,305VENTING MEANS FOR CONTAINERS James W. Kinnavy, Oak Lawn, Ill., and JohnJ. Buchanan,

Pittsburgh, Pa., assignors to Continental 'Can Company,

Inc., New York, N.Y., a corporation of New York Filed Oct. 12, 1966,Ser. No. 586,157 Int. Cl. B65d 25/00; B05b 7/32; F23d 13/ 04 US. Cl.220-89 11 Claims ABSTRACT OF THE DISCLOSURE This disclosure relates to adispensing container having a valve cup secured to a peripheral curl ofa container body by a generally inverted U-shaped peripheral edge whichdefines a chamber with the curl in which is disposed means for forming ahermetic seal at room temperature and also being effective for releasingthe hermetic seal when the container is subjected to elevatedtemperatures whereby media can be vented from within the container andrupture thereof thereby precluded.

Conventional dispensing-type containers are generally charged with aninert noncombustible gaseous propellant which is either admixed with theproduct which is to be dispensed or is confined in a separate chamber.Successive dispensing operations can be carried out until such time asthe dispensing container is emptied of the product, the propellantand/or both the product and the propellant. If, as has been the case,the dispensing container is inadvertently placed into an incinerator orexposed to excessive heat pressure built-up in the container may causethe same to explode. Such explosions can, of course, cause extensiveinjuries to persons in the immediate vicinity of the explosion andshould, if possible, be avoided.

It has been recognized that the probability of explosion is less whenthe dispensing containers are depressurized as compared to situations inwhich the containers are still under internal pressure. Conventionalmechanisms have therefore been provided in pressurized dispensingcontainers for depressurizing the interiors of the containers by ventingthe same to atmosphere. One such known pressure release mechanism is apointed valve stem which punctures the propellant chamber which may be,for example, a collapsible rubber or plastic bag. This puncturing isdesigned to take place after the product has been dispensed from thecontainer but when puncturing takes place earlier complete dispensing ofthe packaged product is precluded. In addition, such puncturingmechanisms for eifecting the pressure release of the propellant aregenerally of a complex construction and are therefore relativelyexpensive to manufacture.

Another pressure release mechanism which is relatively well known is theprovision of a solder-filled hole or aperture in the bottom end closureof a conventional dispensing container. However, due to the relativelyhigh pressure of the propellant and the small surface area to which thesolder is adhered such pressure release mechanisms have provedunsatisfactory and tend to vent the containers prematurely when, forexample, subjected to rough handling in shipment which can loosen thesolder sufficiently to be blown out of the aperture under the influenceof the pressurized propellant.

In keeping with the above it is a primary object of this invention toprovide a novel pressure release mechanism for pressurized dispensingcontainers which overcomes the above and numerous other disadvantages ofconventional pressure release or venting mechanisms, and includes meansbetween a dispensing container and its associated closure for forming ahermetic seal at room temperature and the hermetic sealing meansadditionally including means for releasing the hermetic seal when thecontainer is subjected to temperatures in excess of room temperaturewhereby a gaseous media Within the container body can be vented andexplosion of the container is precluded.

A further object of this invention is to provide a novel mechanism ofthe type immediately heretofore defined wherein the sealing andreleasing means is an admixture of at least two materials, one of thematerials having a relatively low melting point and being capable ofmigrating from the other of the materials when the admixture is heatedto substantially the melting point of the one material whereby a ventarea is provided between the closure and the container through whichfluid pressure is vented to atmosphere.

A further object of this invention is to provide a container of the typeadapted to be vented to atmosphere, the container including a body andan end closure, sealing means between the end closure and the body forforming a hermetic seal at room temperature, and means for releasing theseal when the container is subjected to temperatures in excess of roomtemperature whereby media within the container can be vented toatmosphere and rupture of the container is thereby precluded.

Still another object of this invention is to provide a novel containerof the type heretofore defined wherein the sealing and releasing meansis defined by at least two layers of material disposed in generallysuperimposed relationship, and an outermost one of the layers isconstructed of gas impervious sealing material.

A further object of this invention is to provide a novel container ofthe type heretofore described wherein the two materials are copolymericplastic material, at least one of the materials has a relatively lowmelting point, the one material being capable of migrating from theother of the materials when the admixture is heated generally to themelting point of the one material whereby a vent area is providedbetween the closure and the container body thereby precluding pressurebuild-up internally of the container and the eventual rupture of thelatter.

With the above and other objects in view that will hereinafter appear,the nature of the invention will be more clearly understood by areference to the following detailed description, the appended claims andthe several views illustrated in the accompanying drawing.

In the drawing:

FIGURE 1 is a bottom plan view of a closure constructed in accordancewith this invention provided with a novel pressure venting mechanism,and illustrates the mechanism formed by two superimposed layers ofmaterial housed in an annular channel of the closure.

FIGURE 2 is a highly enlarged fragmentary sectional view taken generallyalong the line 22 of FIGURE 1, and illustrates an outermost layer ofsealing compound material superimposed upon an innermost layer ofmetallic material having a relatively low melting point.

FIGURE 3 is a top perspective view of a dispensing container to whichthe closure of FIGURES l and 2 has been secured, and illustrates a valvemechanism for dispensing a product from the interior of the container onthe influence of a gaseous propellant.

FIGURE 4 is a highly enlarged fragmentary sectional view taken generallyalong the line 44 of FIGURE 3, and illustrates the assembled position ofthe closure and the container body.

FIGURE 5 is an enlarged fragmentary sectional view taken generally alongthe line 44 of FIGURE 3, and illustrates the formation of a vent passagebetween the closure and the container as the metallic material melts andflows outwardly of a channel defined between the closure and thecontainer body.

FIGURE 6 is a fragmentary sectional view of another closure constructedin accordance with this invention taken generally along a line similarto the line 22 of FIG- URE 1, and illustrates a pressure releasemechanism in the form of two admixed materials.

FIGURE 7 is a fragmentary sectional view of another closure taken alonga line corresponding to the line 22 of FIGURE 1, and illustrates anoutermost layer of sealing compound material is partially overlyingrelationship to an innermost layer of metallic material having arelatively low melting point.

Referring first to FIGURE 3 of the drawing, a dispensing containerconstructed in accordance with this invention is generally designated bythe reference numeral 10 and includes a tubular metallic container body11 having a bottom closure (not shown) secured thereto by a conventionaldouble seam 12. An upper dome-like closure 13 is similarly secured tothe container body 11 by a conventional double seam 14. Another closureor valve cap 15 having a cylindrical upstanding steam 16 is secured bymeans 17 (FIGURE 4) to the closure 13. The stem 16 houses a conventionalpush button dispensing valve 20 which dispenses a suitable product (notshown) from an interior 19 of the container body 10.

The closure 15 is best illustrated in FIGURES 1 and 2 of the drawingand, in addition to the central cylindrical stem 16, includes an annularend panel 21 joined by a radius portion 22 (FIGURE 2) to an innermostperipheral wall 23. The peripheral wall 23 is joined by an integral bead24 to a depending peripheral skirt 25. The bead 24, the peripheral skirt25 and the annular wall 24 cooperate to define a generally annulardownwardly opening inverted U-shaped channel 26 housing the pressurerelease mechanism 30 of this invention.

The pressure release mechanism 30 is defined by two superimposed layersof material 31, 32. The layer 31 is sandwiched between the layer 32 anda portion of the bead 24, and is preferably constructed from metallicmaterial having a relatively low melting point, such as low melt solderhaving a melting point ranging between 120160 F. The solder material 31is melted and flowed into the channel 26 when the closure 15 is invertedfrom its normal position, i.e., when the closure 15 is in the positionillustrated in FIGURE 1 of the drawing. When the solder material 31cools it fuses to the innermost wall or surface (unnumbered) of the head24 thereby forming a gas impervious seal between the bead 24 and thematerial 31. In an actual working embodiment of the invention 0.6 gramof molten solder having a melting point ranging between l42-150 F. wasplaced in the channel 26, cooled and solidified after which the layer 32was applied in superimposed relationship in the manner illustrated inFIGURE 2 of the drawing.

The layer 32 is conventional elastomeric sealing compound having amelting point appreciably higher than the melting point of the layer ofmaterial 31 as, for example, 170250 F. The layer 32 of sealing materialmay also be constructed from synthetic thermoplastic material, such asvinyl chloride resins, vinyl acetate resins, styrene resins, acrylateand methacrylate resins, phenolic modified resins, and copolymers ofthese materials. As will be more apparent hereafter, the sole purpose ofthe layer 32 is to effect a hermetic seal between the closure 13 of thecontainer body 11 and the closure 15. Therefore, irrespective of theparticular material from which the layer 32 is constructed, it must beair and gas impervious and also, but not necessarily, of a highermelting point than the layer of metallic material 31.

Prior to charging the container 10 with the product and a suitablegaseous pressurized propellant, the closure 15 is secured to a radiallyoutwardly, downwardly and inwardly directed curl 33 (FIGURE 4) of theclosure 13 by the securing means 17 which is merely a radially outwardlydirected conventional crimp. During the crimping operation the sealingmeans or layer 32 is compressed slightly and a hermetic seal is formedbetween the closures 13 and 15 in the manner clearly illustrated in FIG-URE 4 of the drawing. If after the product has been completely dispensedfrom the container 10 and the latter is accidentally thrown into anincinerator or is otherwise subjected to a relatively high temperature,the layer of metallic material 31 rapidly melts and flows outwardly ofthe channel 26 between the curl 33 and the peripheral skirt 25, in themanner clearly illustrated in FIGURE 5 of the drawing. This permits thepropellant to escape or vent to atmosphere in the manner indicated bythe unnumbered headed arrows in FIGURE 5 thereby precluding the build-upof internal pressure and the subsequent explosion or rupturing of thecontainer 10. In the actual working embodiment of the container 10heretofore noted conventional sealing compound was applied in the mannerillustrated in FIGURE 2 of the drawing after which the closure 15 wascrimped to the closure 13 and charged with a pressurized gaseouspropellant. Thereafter, the pressurized container was subjected to heatand at a temperature of 150 F. the layer of solder 31 flowed out of thechannel 26 in the manner illustrated in FIGURE 5 to release thepropellant to atmosphere.

One major reason for the excellent operability of the venting mechanismheretofore described is the large vent area provided above the entireperiphery of the curl 33 and the bead 24 upon the outward flow of thematerial 31. Prior to being subjected to elevated temperatures theclosure 15 is tightly crimped upon the curl 33 of the closure 13.However, as the material 31 flows outwardly of the channel 26 the tightcrimp between the closures 13, 15 is, in efiect, loosened (FIGURE 5)resulting in the equivalent of a very loose crimp through which thepressurized propellant can readily and rapidly escape to atmosphere.

Another closure constructed in accordance with this invention isillustrated in FIGURE 6 of the drawing and is generally designated bythe reference numeral 45. The closure 45 is basically identical to theclosure 15 of FIG- URES 1-5 of the drawing, and includes an annular wall46, an integral peripheral bead 47 and a peripheral skirt 48 whichcooperate to define an annular downwardly opening generally invertedU-shaped channel 50 corresponding to the channel 26 of the closure 15.However, in lieu of the two superimposed layers 31, 32 of the closure15, the closure 45 includes a single layer 51 of admixed materials whichform a hermetic seal at room temperature and cause this seal to bereleased or break down when the closure 45 is subjected to elevatedtemperatures. The sealing and releasing layer 51 may be, for example, anadmixture of thermosetting and thermoplastic resins. Thenmoset resinsare relatively well known and soften under heat and pressuresubsequently undergoing a chemical change which imparts to them apermanent rigidity and includes, for example, phenol or cresolformaldehyde condensation products, urea formaldehyde condensationproduct, thiourea formaldehyde condensation product, and the aminoresins. The thermoplastic materials include those products heretoforenoted which soften under heat and pressure and include such materials asvinyl chloride resins, vinyl acetate resins, styrene resins, acrylateand methacrylate resins, phenolic modified resins and copolymers ofthese materials. Both the thermoset and the thermoplastic resins areimpervious to gas or air and an admixture thereof would produce aneffective hermetic seal between, for example, the curl 33 of thedispensing container 10 and the bead 47 when the closure 45 is crimpedin the manner heretofore described relative to the closure 15. Byselecting a thermoplastic resin having a lower melting point than thepoint at which the thermoset resin begins to rigidity or set, thethermoplastic resin would migrate from the thermoset resin and flowoutwardly between the skirt 48 and the curl 33 forming the loose crimpheretofore noted and permit gaseous propellant to vent from thecontainer interior to atmosphere. If, for example, the melting point ofthe thermoplastic material or the admixture 51 was F. and thethermosetting point of the thermoset resin was 170 F., the thermoplasticmaterial would flow outwardly from the channel 50* in the mannerheretofore described prior to the thermoset resin becoming permanentlyrigid. Thus, the same venting that is achieved by superimposing thelayers 31, 32 of the closure 15 can be equally obtained by admixingsuitable resins, as in the case of the closure 45.

Another novel closure constructed in accordance with this invention isillustrated in FIGURE 7 of the drawing, and is generally designated bythe reference numeral 55. The closure 55 is substantially identical tothe closure 15 and includes an annular wall 56, an integral downwardlyopening bead 57 and a peripheral skirt 58 defining an annular generallyinverted U-shaped channel 60 corresponding to the channel 26 of theclosure 15. A layer of metallic material 61, corresponding identicallyto the material 31 of the closure 15, is sandwiched between the bead 57and a layer of material 62 corresponding to the layer 32 of the closure15. However, the layer of sealing material 62 does not completelyoverlie the layer of metallic release material 61 and annular portion63, 64 of the latter are exposed in the manner clearly illustrated inFIGURE 7. When the closure 55 is applied to a dispensing container inthe manner heretofore described relative to FIGURE 4 of the drawing, ahermetic seal is formed between the curl 33 and the sealing materiallayer 62 which prevents the propellant from escaping between the curland the lowermost surface of the layer 61 under normal room temperatureconditions. Since the meallic material 61 is applied to the bead 57 in amolten condition when the closure 55 is inverted the layer 61 is fusedto the bead 57 and propellant cannot escape between opposed surfaces ofthe layer 61 and the bead 57. However, when the container is subjectedto elevated temperatures the metallic material 61 melts and readilyflows outwardly between the curl 33 and the peripheral skirt 58 in thesame manner as that described relative to the closure 15. However, sincethe layer of sealing material 62 does not completely overlie the layerof release material 61 the latter can flow more rapidly outwardly toachieve a more rapid vent area between the curl 33 and the closure 55and thus more rapidly vent pressurized propellant from the container toatmosphere.

What is claimed is:

1. A container comprising a container body and an end closure, saidcontainer body terminating in a radially outwardly and upwardly andinwardly and downwardly directed curl, said end closure including an endpanel terminating at a peripheral ege portion, said peripheral edgeportion including a peripheral curl directed radially upwardly outwardlyand then downwardly terminating at a peripheral skirt to define withsaid container body curl a generally annular chamber, means securingsaid curls to each other, said end panel including aperture means inwhich is received a valve operative dispensing mechanism, and means insaid annular chamber forming a hermetic seal at room temperature andbeing also effective for releasing the hermetic seal when the containeris subjected to temperatures in excess of room temperature whereby mediacan be vented from within the container and the rupture thereof isprecluded.

2. The container as defined in claim 1 wherein said sealing andreleasing means is an admixture of at least two materials, and one ofsaid materials is gas impervious sealing material.

3. The container as defined in claim 1 wherein said sealing andreleasing means is defined by at least two layers of material disposedin generally superimposed relationship, and an outermost one of saidlayers is constructed of gas impervious sealing material.

4. The container as defined in claim 1 wherein said sealing andreleasing means is an admixture of at least two materials, and one ofsaid materials is gas imprevious sealing material.

5. The container as defined in claim 1 wherein said sealing andreleasing means is defined by at least two layers of material housed ingenerally superimposed relationship in said chamber, and an outermostone of said layers is constructed of gas impervious sealing material.

6. The container as defined in claim 2 wherein said two materials arecopolymeric plastic materials, at least one of said materials having arelatively low melting point, and said one material being capable ofmigrating from the other of the materials when the admixture is heatedgenerally to said melting point whereby a vent area is provided betweenthe closure and the container body thereby precluding rupture of thelatter under the influence of pressure build-up internally of thecontainer.

7. The container as definedin claim 3 wherein an innermost one of saidlayers is constructed from metallic material.

8. A closure adapted for use with a container to prevent the containerfrom rupturing when subjected to elevated temperatures comprising an endpanel terminating in a peripheral edge portion, said peripheral edgeportion including a peripheral curl directed radially upwardly outwardlyand then downwardly terminating at a peripheral skirt to define agenerally annular downwardly-opening chamber, means wholly within saidchamber for forming a hermetic seal at room temperature with a containerbody to which the closure is adapted to be secured, said last-mentionedmeans being also elfective for releasing the hermetic seal when thecontainer is subjected to temperature in excess of room temperaturewhereby media can be vented from within the container and rupturethereof is precluded, said sealing and releasing means being anadmixture of at least two materials, and one of said materials is gasimpervious sealing material.

9. A closure adapted for use with a container to prevent the containerfrom rupturing when subjected to elevated temperatures comprising an endpanel terminating in a peripheral edge portion, said peripheral edgeportion including a peripheral curl directed radially upwardly outwardlyand then downwardly terminating at a peripheral skirt to define agenerally annular downwardly opening chamber, means wholly within saidchamber for forming a hermetic seal at room temperature with a containerbody to which the closure is adapted to be secured, said last-mentionedmeans being also effective for releasing the hermetic seal when thecontainer is subjected to term perature in excess of room temperaturewhereby media can be vented from within the container and rupturethereof is precluded, said sealing and releasing means being defined byat least two layers of material housed in generally superimposedrelationship in said chamber, and an outermost one of said layers isconstructed of gas impervious sealing material.

10. A closure adapted for use with a container to prevent the containerfrom rupturing when subjected to elevated temperatures comprising an endpanel terminating in a peripheral edge portion, said peripheral edgeportion including a peripheral curl directed radially upwardly outwardlyand then downwardly terminating at a peripheral skirt to define agenerally annular downwardly opening chamber, means wholly within saidchamber for forming a hermetic seal at room temperature with a containerbody to which the closure is adapted to be secured, said lastmentionedmeans being also effective for releasing the hermetic seal when thecontainer is subjected to temperature in excess of room temperaturewhereby media can be vented from within the container and rupturethereof is precluded, said sealing and releasing means comprise at leasttwo layers of material housed in generally superimposed relationship insaid chamber, an innermost of said layers being metallic material havinga relatively low melting point, and an outermost of said layers beingconstructed of gas impervious sealing material.

11. A closure adapted for use with a container to prevent the containerfrom rupturing when subjected to elevated temperatures comprising an endpanel terminating in a peripheral edge portion, said peripheral edgeportion including a peripheral curl directed radially upwardly outwardlyand then downwardly terminating at a peripheral skirt to define agenerally annular downwardly opening chamber, means wholly within saidchamber for forming a hermetic seal at room temperature with a containerbody to which the closure is adapted to be secured, said lastmentionedmeans being also effective for releasing the hermetic seal when thecontainer is subjected to temperature in excess of room temperaturewhereby media can be vented from within the container and rupturethereof is precluded, said sealing and releasing means is an admixtureof at least two materials, at least one of said materials having arelatively low melting point, and said one material being capable ofmigrating from the other of said materials when the admixture is heatedgenerally to said melting point whereby a vent area is provided betweenthe peripheral edge portion of the closure and an associated containerthereby precluding rupture of the latter under the influence of pressurebuild-up internally of the container.

8 References Cited UNITED STATES PATENTS 900,763 10/ 1908 McNott.

908,140 12/1908 Rigby 220-81 2,128,091 8/193 8 Iversen et a1. 2,500,1193/ 1950 Cooper. 2,743,036 4/ 1956 Wachtell. 2,822,961 2/ 1958 Seaquist.3,081,906 3/1963 Henchert 220-81 X 3,245,578 4/ 1966 Sutton. 2,177,96310/ 1939 Stover 169-26 2,986,319 5/1961 Bierman et al.

RAPHAEL H. SCHWARTZ, Primary Examiner.

US. Cl. X.R.

